Virtually all known attempts to formalize, at least partially, Putnam's two-stage proof contained in his famous article Time and Physical Geometry, follow Stein's advice to interpret the relation R as ”x is real to y”. However, Putnam has explicitly rejected this interpretation, stating that it ”misses the issue” he was addressing. The present attempt to formalize the proof regards reality as an absolute property, in accord with Putnam's intention. The formalization reveals both the strength and the weak point of his reasoning. On the one hand, it shows that the popular assumption that ”all and only things that exist now are real” is incompatible with Special Relativity in its standard interpretation. What is more, its weaker version "all t...